MODELLI DIETETICI PER LA PROMOZIONE DEL CALO PONDERALE: CONFRONTO BASATO SULL EVIDENZA Giorgio Bedogni Obiettivo Confrontare l efficacia dei modelli dietetici per l ottenimento di un calo ponderale a lungo termine nell adulto Unità di Epidemiologia Clinica Centro Studi Fegato Basovizza (TS) Posizione ADA 2009 ADA EAL 2006
Approcci dietetici Approcci dietetici Indice glicemico Indice glicemico A low glycemic index diet is not recommended for weight loss or weight maintenance as part of a comprehensive weight management program since it has not been shown to be effective in these areas Rating: STRONG, IMPERATIVE Seagle et al. JADA 2009;109:334
Indice glicemico Indice glicemico Thomas D et al. Cochrane Database of Systematic Reviews 2007, 3 : CD005105. Indice glicemico Approcci dietetici A low glycemic index diet is not recommended for weight loss or weight maintenance as part of a comprehensive weight management program since it has not been shown to be effective in these areas Rating: STRONG, IMPERATIVE Seagle et al. JADA 2009;109:334
Carboidrati Low-carb vs. high-carb Consumption of a low-carbohydrate diet is associated with a greater weight and fat loss than traditional reduced-calorie diet during the first 6 months, but these differences are not significant after 1 year Rating: FAIR, CONDITIONAL Seagle et al. JADA 2009;109:334 Low-carb vs. high-carb Low-carb vs. high-carb
Carboidrati Low-carb vs. high-carb Evidence from this systematic review demonstrates that low-carbohydrate/high-protein diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year. More evidence and longer-term studies are needed to assess the long-term cardiovascular benefits from the weight loss achieved using these diets. DIRECT Disegno di studio Tre gruppi di trattamento Tutti 1500/1800 kcal (donne/uomini) Low-fat diet (American Heart Association): FAT = 30% E, SFA = 10% E, CH = 300 mg/die Mediterranean Diet (Willett): FAT = 35%; olio di oliva 30-45 g/die;! 20/die g noci o noccioli Low-carbohydrate diet (Atkins): CHO 20 g/die -> 120 g/die; nessuna limitazione di proteine e grassi (preferire FAT vegetali ed evitare TFA)
DIRECT DIRECT Shai et al. New Engl J Med 2008;359:229 DIRECT WHI The more favorable effects on lipids (with the lowcarbohydrate diet) and on glycemic control (with the Mediterranean diet) suggests that personal preferences might inform individual tailoring of dietary interventions
Disegno dello studio 4 gruppi sperimentali (disegno fattoriale) FAT 20% PRO 15% CHO 65% FAT 20% PRO 25% CHO 55% FAT 40% PRO 15% CHO 25% FAT 40% PRO 25% CHO 35% Disegno dello studio Disegno dello studio Obiettivi comuni ai 4 gruppi Deficit di 750 kcal rispetto al dispendio energetico (calorimetria + attività fisica) SFA! 8% E Fibra 20 g/die Carboidrati a basso indice glicemico Supporto gruppo 1 v. / 7 gg. -> 3 v. / 4 sett. -> 2 v. /4 sett. Supporto individuale 1 v. / 8 sett. Attività fisica 90 minuti / sett.
Outcome primario Outcome secondario Altri outcome Altri outcome All the diets reduced risk factors for cardiovascular disease and diabetes at 6 months and 2 years. At 2 years, the two low-fat diets and the highest-carbohydrate diet decreased low-density lipoprotein cholesterol levels more than did the high-fat diets or the lowest-carbohydrate diet (lowfat vs. high-fat, 5% vs. 1% [P = 0.001]; highest- carbohydrate vs. lowest-carbohydrate, 6% vs. 1%[P = 0.01]). The lowest-carbohydrate diet increased HDL cholesterol levels more than the highest-carbohydrate diet (9% vs. 6%, P = 0.02). All the diets decreased triglyceride levels similarly, by 12 to 17%. All the diets except the one with the highest carbohydrate content decreased fasting serum insulin levels by 6 to 12%; the decrease was larger with the high-protein diet than with the average-protein diet (10% vs. 4%, P=0.07). Blood pressure decreased from baseline by 1 to 2 mm Hg, with no significant differences among the groups (P>0.59 for all comparisons).
Soddisfazione Conclusione Craving, fullness, and hunger and diet-satisfaction scores were similar at 6 months and at 2 years among the diets. Attendance at group sessions strongly predicted weight loss at 2 years (0.2 kg for every session attended) and was similar among the diet groups (p = 0.22 for a test of difference in slopes. The participants were eager to lose weight and to attempt whatever type of diet they were assigned, and they did well in screening interviews and questionnaires that evaluated their motivation. Thus, the findings should be directly applicable to both clinicians recommendations for weight loss in individual patients and the development of population-wide recommendations by public health officials DIOGENES Disegno di studio Trial randomizzato controllato Multicentrico Danimarca, Paesi Bassi, Regno Unito, Grecia, Germania, Spagna, Bulgaria e Repubblica Ceca Sponsorizzato dalla Comunità Europea
Trattamenti Low-PRO = 13% vs. High-PRO = 25% High-GI = Low-GI + 15 Nessuna restrizione energetica Counseling dietetico 1 v. / 2 settimane per 6 mesi -> 1 v. / 30 gg successivamente
Low-carb vs. high-carb? Low-carb vs. high-carb? Carboidrati Consumption of a low-carbohydrate diet is associated with a greater weight and fat loss than traditional reduced-calorie diet during the first 6 months, but these differences are not significant after 1 year Rating: FAIR, CONDITIONAL Seagle et al. JADA 2009;109:334
Mediterranean score Posizione ADA It is the position of the ADA that successful weight loss management to improve overall health for adults require a lifelong commitment to healthful lifestyle behaviors emphasizing sustainable and enjoyable eating practices and daily physical activity Seagle et al. JADA 2009;109:330 Trichopoulou A et al. BMJ 1995;311:1457. Trichopoulou A et al. N Engl J Med 2003;348:2599. Centralità del paziente Evidence-based practice The partnership between RDs and their patients should focus on developing strategies that will enhance opportunities for clients to control their own behaviors related to overweight or obesity Seagle et al. JADA 2009;109:330 Haynes RB. ACP Journal Club 2002;136:A11
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